Question 65
HardOriginal questionA community centre runs six one-day workshops in one week from Monday to Sunday: coding, dance, painting, photography, pottery and yoga. Each workshop is held on a different day, and on the remaining day no workshop is held. 'Before' or 'after' means on any earlier or later day; 'immediately before' or 'immediately after' means the previous or the next day. When counting the days between two workshops, count every day in between, including the day with no workshop. The following is known:
1. The day with no workshop comes immediately after the coding workshop.
2. Painting is held on the last day of the week.
3. Exactly two days lie between the yoga workshop and the pottery workshop.
4. Dance is held on the day immediately after pottery.
5. Photography is held on some day after dance, and coding on some day before pottery.
6. The yoga workshop is held before the coding workshop.
Which one of the clues could be left out and the whole schedule would still be fixed?
Show the answer and explanation
Correct answer: B
Explanation
The solving above never used the clue about two days between yoga and pottery; it simply holds in the result (Monday and Thursday, with Tuesday and Wednesday between).
Without the free-day clue, coding and the free day could swap (free Tuesday, coding Wednesday).
Without the dance clue, dance could move to Monday with yoga, coding, the free day, pottery and photography after it. Without the yoga clue, yoga could move to Saturday with coding on Monday.
So only the yoga and pottery clue can be removed.
Worth noting
Before you answer, write the solution path and note which clues it used. An unused clue is the candidate; test the others by finding a second arrangement.
- Concept
- Spotting a redundant clue
- Typical timeTypical
- 140 s
- Your timeYours
- —
Ten questions from Puzzles, at your own pace.